New to OOP and in need of clarification!

I am new to OOP and have a only vague understanding of C. I am trying to learn from the iTunes U videos but have stumbled upon a sticking point:

regarding IBAction and IBOutlet, from a controller objects point of view, which does what? (In my old school mind these are like BASIC's peek (an address) and poke (an address) is this wrong?)

I am trying to recreate the slider demonstration where a label displays the sliders value but my version of xCode is not like in the demo and I am confused about how to wire the objects and which IB objects to use.

So I create a new project called test, goto the testViewController.xib which opens Interface Builder and I drag over a slider and label... I then goto xCode and under File > New File... > Object C Object (call it "updater") and goto the updater.h file. Here I define IBOutlets and an IBAction for the slider and the label...